Field of the Invention
The present invention relates to an electric current detector.
Description of the Related Art
A certain electric current sensor based on a magnetic balance system includes a vertical-type (that is, vertically placed) annular core, a primary conductor is arranged so as to interlink with that annular core, and a compensating coil (secondary coil) is installed on the annular core. Further, a cavity is provided at the bottom portion of the annular core and a stick-shaped fluxgate-type sensor is inserted into that cavity. A control circuit board for driving that sensor is provided separately from the circuit board on which this electric current sensor is mounted and is connected to that sensor (for example, see Patent Document 1: Japanese unexamined PCT publication No. 2011-510318).
On the other hand, for the fluxgate-type magnetic sensor, other than the above-mentioned rod-shaped sensor for a special application, there exists an IC-chip shaped sensor with a built-in circuit structure as described, for example, in Patent Document 2 (US unexamined patent publication No. 2014/0218018).